Submission #985057

#	Time	Username	Problem	Language	Result	Execution time	Memory
985057		Tsagana	Circle selection (APIO18_circle_selection)	C++14	100 / 100	1907 ms	55172 KiB

circle_selection

#include<bits/stdc++.h>

#define IOS ios_base::sync_with_stdio(false);cin.tie();cout.tie();
#define all(x) x.begin(), x.end()
#define int long long
#define pi pair<int, int >
#define pq priority_queue
#define lb lower_bound
#define ub upper_bound
#define pb push_back
#define eb emplace_back
#define mset multiset
#define F first
#define S second

using namespace std;

struct circle {
	int x, y, r;
	void init() {cin >> x >> y >> r;}
};
circle C[300001];
int n, mx, ans[300001];
map<pair<int, int>, vector<int>> mp;
 
bool check(int i, int j) {
	int d = (C[i].x - C[j].x) * (C[i].x - C[j].x);
	d += (C[i].y - C[j].y) * (C[i].y - C[j].y);
	return (d <= (C[i].r + C[j].r) * (C[i].r + C[j].r));
}
void build() {mp.clear();
	for (int i = 1; i <= n; i++) if (!ans[i]) mp[{C[i].x/mx, C[i].y/mx}].pb(i);
}
bool cmp(int a, int b) {return (C[a].r >  C[b].r || (C[a].r == C[b].r && a < b));}
void solve() {
	cin >> n; for (int i = 1; i <= n; i++)
	{C[i].init(); C[i].x += 1e9; C[i].y += 1e9; mx = max(mx, C[i].r);}
	vector<int> v(n); iota(all(v), 1); sort(all(v), cmp); build();
	for (int i: v) {
		if  (ans[i]) continue;
		if  (C[i].r <= mx / 2) {mx /= 2; build();}
		for (int j = C[i].x/mx-2; j <= C[i].x/mx+2; j++)
		for (int k = C[i].y/mx-2; k <= C[i].y/mx+2; k++) {
			if (!mp.count({j, k})) continue;
			for (int l: mp[{j, k}]) if (!ans[l] && check(i, l)) ans[l] = i;
		}
	}
	for (int i = 1; i <= n; i++) cout << ans[i] << ' ';
}
signed main() {IOS solve(); return 0;}

• Subtask 1: 7 / 7
• Subtask 2: 12 / 12
• Subtask 3: 15 / 15
• Subtask 4: 23 / 23
• Subtask 5: 30 / 30
• Subtask 6: 13 / 13